The present invention relates to photo-analysis apparatus and more particularly to photo-responsive apparatus for detecting various characteristics of small particles.
There is a great need for accurate analysis of the characteristics of groups of small particles. A particularly important field for such analysis is in medical research and diagnosis. In this field, blood cells and other biological cells must be analyzed.
Many different types of apparatus have been employed to analyze small particles such as blood cells. When a number of characteristics of each cell are to be analyzed, optical analyzers are often employed. In this type of an apparatus, particles entrained in a very thin stream of liquid are passed one by one in the stream through an optical scanning station. Two or more photo-optical detecting devices are arranged to detect the optical reaction of each particle to illumination from a beam of light cast through the optical scanning station. One detecting device measures the amount of fluorescence generated by passage of a particle through the beam of light, and a second detecting device measures the light scattered by passage of a particle through the beam of light.
In apparatus of this type, adjustment of the relative positions of the photo-optical detecting devices, the stream of liquid with particles therein, and the light beam is extremely critical. Generally, one optical device, the fluorescence detector, is first aligned with the stream of liquid visually. The stream of liquid and the light beam are then aligned and the first photo-optical detecting device, the stream of liquid and the light beam all are again aligned with respect to one another in order to maximize the amount of light received by the detecting device.
The second photo-optical detecting device is then visually aligned with the liquid stream and with the light beam. Then its position is adjusted to maximize the light received at the photo-optical detecting device. Then all of the various structures are realigned with respect to one another by slight adjustments on each one in sequence until the alignment of all of the devices results in the maximum obtainable outputs.
It should be noted, however, that the maximum obtainable output of any one detector may not signify an optimized alignment, and an optimized alignment, because of the configuration of each structure, may not be possible. It should also be noted that the above described procedure for adjusting the apparatus is extremely difficult and time consuming, wasting time which could be more effectively utilized for actual testing procedures.